Table of Contents

• About
• Why Alkindi?
• Installation
• Quick Start
  • Key Encapsulation (ML-KEM)
  • Digital Signatures (ML-DSA / SLH-DSA)
  • Key Serialization (DER/PEM)
• Documentation
• Contributing
• License
• Acknowledgments

About

The project is named after Alkindi (الكِنْدي), the 9th-century Arab Muslim polymath who pioneered cryptanalysis and frequency analysis, laying the foundations for modern cryptography.

Alkindi makes quantum-resistant cryptography straightforward and accessible in Python by providing clean, type-safe bindings to OpenSSL's implementations of NIST-standardized post-quantum algorithms. As quantum computers advance, traditional public-key systems like RSA and elliptic curves become vulnerable. Alkindi provides the cryptographic primitives needed to protect against both classical and quantum attacks.

Supported Algorithms

• ML-KEM (formerly Kyber) — Key encapsulation mechanisms for secure key exchange
  Based on lattice cryptography, ML-KEM enables two parties to establish a shared secret over an insecure channel. Available in three security levels (ML-KEM-512, ML-KEM-768, ML-KEM-1024) corresponding to AES-128, AES-192, and AES-256 equivalent security.

• ML-DSA (formerly Dilithium) — Digital signatures for authentication and integrity
  Lattice-based signatures that provide quantum-resistant authentication. Three parameter sets (ML-DSA-44, ML-DSA-65, ML-DSA-87) offer balanced trade-offs between signature size and security strength.

• SLH-DSA (formerly SPHINCS+) — Hash-based signatures for conservative security guarantees
  Unlike lattice-based schemes, SLH-DSA relies only on hash function security, making it ideal for long-term signatures and applications requiring minimal cryptographic assumptions. Available in multiple variants optimized for either speed or size.

Alkindi uses CFFI to interface directly with OpenSSL's C implementations, achieving high performance with minimal overhead. The library provides a thread-safe API with full type annotations for enhanced developer experience.

Status: Alpha — Alkindi is under active development with the explicit goal of becoming a production-grade, thoroughly reviewed PQC library for Python. APIs may change before version 1.0.0.

Why Alkindi?

Alkindi bridges the gap between enterprise-grade cryptography and Python developer ergonomics, bringing NIST-standardized post-quantum algorithms to your applications with production readiness in mind:

Installation

From PyPI (Coming Soon)

pip install alkindi

From Source

Requirements: Python 3.10+ and C compiler

# Clone the repository
git clone https://github.com/alraddady/alkindi.git
cd alkindi

# Build OpenSSL with PQC support
./scripts/build_openssl.sh

# Install Alkindi
pip install -e .

# Or install with development dependencies
pip install -e ".[dev]"

Quick Start

Key Encapsulation (ML-KEM)

from alkindi import KEM

# Generate a keypair for the receiver
keypair = KEM.generate_keypair("ML-KEM-768")

# Sender: encapsulate a shared secret
ciphertext, shared_secret_sender = KEM.encapsulate("ML-KEM-768", keypair.public_key)

# Receiver: decapsulate to recover the shared secret
shared_secret_receiver = KEM.decapsulate("ML-KEM-768", keypair.private_key, ciphertext)

# Both parties now share the same secret
assert shared_secret_sender == shared_secret_receiver

Deterministic Key Generation

Pass a 64-byte seed to produce the same keypair every time. The seed is the concatenation of the two FIPS 203 internal seeds d || z.

import os

seed = os.urandom(64)
keypair = KEM.generate_keypair("ML-KEM-768", seed=seed)
keypair2 = KEM.generate_keypair("ML-KEM-768", seed=seed)
assert keypair.public_key == keypair2.public_key

Digital Signatures (ML-DSA / SLH-DSA)

from alkindi import Signature

# Generate a keypair for the signer
keypair = Signature.generate_keypair("ML-DSA-65")

# Sign a message
message = b"Hello, quantum world!"
signature = Signature.sign("ML-DSA-65", keypair.private_key, message)

# Verify the signature
is_valid = Signature.verify("ML-DSA-65", keypair.public_key, message, signature)
print(f"Signature valid: {is_valid}")  # True

# Tampering detection
is_valid = Signature.verify("ML-DSA-65", keypair.public_key, b"Tampered message", signature)
print(f"Tampered signature valid: {is_valid}")  # False

Context Strings

ML-DSA and SLH-DSA support an optional context string (up to 255 bytes) that is cryptographically bound to the signature. The same context must be supplied at both signing and verification time.

ctx = b"the quick brown fox jumps over the lazy dog"
signature = Signature.sign("ML-DSA-65", keypair.private_key, message, context=ctx)

# Verification succeeds only with the correct context
Signature.verify("ML-DSA-65", keypair.public_key, message, signature, context=ctx)   # True
Signature.verify("ML-DSA-65", keypair.public_key, message, signature)                 # False

Key Serialization (DER/PEM)

Keys converts raw key bytes to and from standard wire formats for storage and interoperability:

• Public keys → SubjectPublicKeyInfo (SPKI / X.509)
• Private keys → PKCS#8 PrivateKeyInfo (unencrypted)

from alkindi import KEM, Keys

keypair = KEM.generate_keypair("ML-KEM-768")
keys = Keys("ML-KEM-768")

# Export to DER or PEM
public_pem  = keys.public_key_to_pem(keypair.public_key)
private_der = keys.private_key_to_der(keypair.private_key)

# Import back to raw bytes
public_key  = keys.public_key_from_pem(public_pem)
private_key = keys.private_key_from_der(private_der)

Keys works with all ML-KEM, ML-DSA, and SLH-DSA algorithms. Bind it once to an algorithm, then call encode/decode methods without repeating the algorithm name.

Documentation

Algorithm Selection Guide

Choosing the right algorithm and parameter set depends on your security requirements, performance constraints, and use case. For detailed guidance on selecting appropriate algorithms, see the Algorithm Selection Guide.

NIST Standards

• FIPS 203: Module-Lattice-Based Key-Encapsulation Mechanism
• FIPS 204: Module-Lattice-Based Digital Signature Standard
• FIPS 205: Stateless Hash-Based Digital Signature Standard

Additional Resources

• OpenSSL Documentation
• NIST Post-Quantum Cryptography Project

Contributing

Contributions are welcome! Please review our Contributing Guidelines before submitting pull requests or opening issues.

License

Licensed under the Apache License 2.0. See LICENSE for complete terms.

Acknowledgments

Alkindi stands on the shoulders of giants. I would like to thank the following organizations and teams for their foundational work:

• National Institute of Standards and Technology (NIST): for standardizing post-quantum cryptography
• OpenSSL Project: for providing the cryptographic foundation
• Algorithm Development Teams:
  • Kyber developers
  • Dilithium developers
  • SPHINCS+ developers
• Open Quantum Safe (OQS): for their pioneering work in making post-quantum cryptography practical and for fostering a welcoming community

My sincere gratitude also extends to the broader open-source community, whose collaborative spirit and tireless contributions make projects like this possible.